If you use Microsoft's accessibility features and want a free upgrade to Windows 10, better hurry up because Microsoft is closing this last deal on December 31.

Microsoft mostly stopped offering free upgrades to Windows 10 in July last year but users who use accessibility features, got an extension of that promo, a report in ZDNet said on Saturday.

Accessibility features in Windows are options to help users who may have trouble using their computers normally.

In July, Microsoft announced: "We are not restricting the free upgrade offer to specific assistive technologies. If you use assistive technology on Windows, you are eligible for the free upgrade offer."

According to the report, Microsoft quietly edited that page last week and updated the original statement "We will make a public announcement prior to ending the offer" to "The accessibility upgrade offer expires on December 31, 2017".

The general 'Upgrade to Windows 10 FAQ' page was revised to include the expiration date for this offer. That page was 'last reviewed' on October 24.

Microsoft started rolling out the Windows 10 Fall Creators Update last month, bringing several new features to the platform. Alongside, the company also announced that the first mixed reality headsets were now available to buy.

The biggest change comes in the form of the Fluent Design System, reworking the way cross-platform apps look and behave on Windows 10. Also new, is Story Remix for easy video editing, a cloud-powered Clipboard, and OneDrive Files On-Demand, among other new features.